| 摘要 |
<p>A non-gelled copolymer is prepared from: I) at least one ethylenically unsaturated aliphatic or aromatic monomer that is unsubstituted with reactive functionality and/or has hydroxyl functionality; II) an ethylenically unsaturated monomer having one acid functional group; and III) an ethylenically unsaturated oligomeric monomer having a number average molecular weight of about 1500 to about 4000 and which is derived from a hydroxyl functional acid having a predominantly hydrocarbon chain of from about 10 to 19 carbon atoms. The amounts of the monomers based upon the total solid weight of reactants used to prepare the copolymer are: about 80 to about 95 percent for I; about 3 to about 6 percent for II; and about 2 to about 14 percent for III. The ungelled copolymer can be present with hydrophobic amorphous fumed silica in amounts of about 50 to about 90 for the copolymer and about 10 to about 50 for the silica all as percentages by weight based on the weight of the two components. The ungelled copolymer alone or with the silica can be present along with coating components like film forming polymers, aqueous and/or organic solvent vehicles and optionally one or more pigments. In the colored and/or clear coating compositions and in the methods of their application to substrates, the amount of the silica is up to about 2.5 percent by weight, and the ratio of the copolymer to the silica is generally in the range of from about 9:1 to 1:1 to yield coatings with good rheology control.</p> |
